Federal law precludes job discrimination due to ethnic or racial identity and a host of other factors, but they do not include sexual orientation or gender identity.

States also have employment anti-discrimination laws, but there is a wide mix of the degrees of protection they offer and more than half do not bar discrimination based on sexual orientation. Pennsylvania, for example, formally bans discrimination based on sexual orientation or gender identity only in public employment.

The vast disparities in protection mandate a comprehensive federal law, just like those that uniformly bar discrimination based on race.

Tuesday, the Senate Health, Education, Labor and Pensions approved such a law, the Employment Non-Discrimination Act, by a bipartisan 15-7 vote. It would proscribe discrimination against gay and transgender employees, exactly as other federal law proscribes discrimination based on race, sex, religion or ethnicity.

"Employees should be judged on their skills and abilities in the workplace, and not on their sexual orientation or gender identity," said Sen. Bob Casey, a cosponsor.

Many companies, including at least 440 of the Fortune 500, already have such anti-discrimination policies. And federal agencies have attempted administratively to use existing civil rights laws to cover anti-gay workplace discrimination.

But ENDA is the best way to ensure that the protections are uniform. Congress should pass it.